Air conditioning system heater assembly



July 16, 1963 G. A. RAYMOND AIR CONDITIONING SYSTEM HEATER ASSEMBLYFiled May 26. 1960 FIG. 2

INVENTOR. GLENDON A. RAYMOND ATTORNEY United States Patent 3,08,145 AmCGNDITKUNING SYSTEM HEATER ASSEMBLY Glendon A. Raymond, Fuilton, N.Y.,assignor to Carrier Corporation, Syracuse, N.Y., a corporation ofDelaware Filed May 26, 1960, Ser. No. 31,994 1 Claim. (Q1. 219-414;)

This invention relates generally to air conditioning systems havingreverse cycle refrigeration systems for heating and cooling indoor airand more particularly to a novel auxiliary heating assembly forimproving the air heating performance of such air conditioning systems.

A common type of air conditioning system employed for residential andcommercial use includes a reverse cycle refrigeration system comprisinga compressor, an indoor air heat exchange coil, expansion means, anoutdoor air heat exchange coil and a valve for reversing the flow ofrefrigerant through the coils. Suitable duct work connects the indoorair heat exchange coil with the area to be conditioned. The indoor coilis used as an air cooling evaporator during the cooling cycle and as anair heating condenser during the heating cycle. The indoor air heatexchange coil under certain circumstances does not provide adequate heatduring the heating cycle. As a consequence, electric resistance heatershave been provided adjacent the indoor air heat exchange coil to supplyauxiliary heat to comfortably heat the room. These heaters have usuallybeen placed Within the indoor section of the heat pump. Often the indoorsection is placed within a closet or other confined area and the heaterstherein are relatively inaccessible for repair and maintenance. In somecases, the entire indoor section must be removed from the confined areaand in other instances the covers must be removed from the indoorsection.

The primary object of this invention is to provide an air conditioningsystem with an improved heating assembly in which the disadvantages ordeficiencies in prior constructions are obviated.

A further object of this invention is to provide an air conditioningsystem having a reverse cycle refrigeration system with simplified meansfor mounting the auxiliary heater employed therewith.

Another object of the present invention is to provide an airconditioning system with a novel heating assembly adapted to bedetachably mounted in the duct work of such system.

Still another object of the present invention is to provide an airconditioning system with a novel heating assembly including adrawer-type frame mounting the heater element to simplify themaintenance and repair of the heater element.

Another object of this invention is to provide an air conditioningsystem with an improved heating assembly that is of simple design andthat can be fabricated easily and inexpensively.

This invention relates to an air conditioning system including a casinghaving an air inlet and an air outlet, means for cooling air passingthrough the casing, a duct for conducting air from the casing to an areato be treated and a heating assembly for heating air passing through theduct. The heating assembly comprises an outer frame and an inner frame.The outer frame connects one end of the duct with the air outlet in thecasing. The outer frame includes a pair of inwardly-facing channelmembers extending in parallel relation one to the other. The

\ inner frame includes side members slidably supported on said channelmembers and a long helical coil of resistance wires mounted on saidinner frame, the helical coil adapted to be supplied with electriccurrent. Means detachably connect the outer frame and the inner frame sothat 3,fi%,145 Patented July 16, 1963 ice the inner frame may be easilyremoved from the outer frame for repair and maintenance of the helicalcoil.

In the accompanying drawing which illustrates a preferred form of thepresent invention, like numerals refer to like parts throughout thesever-a1 views.

FIGURE 1 is a perspective view of a portion of the air conditioningisystem embodying the present invention;

FIGURE 2 is a sectional view of the heating assembly of the presentinvention taken along the plane 11-11 of FIGURE 1, and

FIGURE 3 is a cross-sectional view of the heating assembly taken alongthe line IIIIII of FIGURE 2.

Referring to FIGURE 1, there is shown the indoor section of an airconditioning system. The indoor section comprises a casing 2 having anair inlet 3 and an air outlet 4. Within the casing are mounted a pair ofheat exchange coils 5 and 6. These coils are connected in a conventionalreverse cycle or heat pump refrigeration system comprising a compressor,an outdoor heat exchange coil, expansion means as, for example, athermal expansion valve and a reversing valve for selectively directingrefrigerant first through indoor heat exchange coil or the outdoor heatexchange coil. These elements of the heat pump system are not shown asthey are conventional and do not form any part of the present invention.

Air inlet 3 is in communication with a duct 7 which supplies air to thecasing from the room to be conditioned. A heating assembly 8 is incommunication at one end with the air outlet 4 and at the other end witha duct 9 which conducts treated air to the room to be air conditioned.

The heating assembly shown more clearly in FIG- URES 2 and 3 comprisesan outer frame 10 and an inner frame 11. The outer frame includesU-shaped side members 12 and 14 and a rear member 18, suitably connectedthereto as, for example, by spot welding. Extending from the lowerextremity of the central portion of each side member 12, 14 is a flange13, 15. Each flange 13, 15 is connected to the side member next belowbysuitable connecting means, as for example, screws 16 and the flangeson the lowermost outer frame engage a raised lip 17 defining the airoutlet 4 in casing 2. The ends of each U-shaped side member areconnected together by support members 19 and 29. The support members arepreferably inwardly-facing channel members as shown in FIG- URE 3,though other configurations as, for example, angle members may besatisfactorily used.

Duct 9 has a flange 9 depending from opposite sides thereof affixed byscrews 9" to the uppermost outer frame 10 (FIGURE 1).

The inner frame comprises side members 21, 22, rear member 23 and atransverse brace member 24. The side members are slidably supported onthe support members 19 and 20.

Rods 25, 26 and 27 are secured to the inner frame and extend from frontto rear thereof between transverse brace member 24 and rear member 23.Mounted on each rod are a plurality of supports 28. These supports,which may be of generally U-shaped configuration, have eyes 29 definedon each end. Within each eye is supported a ceramic insulator 30. Ahelical coil 31 of resistance wire is circuitously supported within theinsulators 30. The ends of the long helical coil 31 are connected toterminal stems 32 and 33. Each terminal stem is mounted within aseparate electrical insulator 34, and 35, respectively, secured to thetransverse brace member 24. Leads 36 and 37 extend forwardly from theterminal stems 32 and 33 and are approximately connected to an electriccontrol within control box assembly 38 which forms the front portion ofthe inner frame. Control box assembly 38 comprises a casing 39 which isconnected to the side members of inner frame 11. Removable cover 40closes the front of casing 39. Mounted to each side of casing 39 andforming a part thereof are the flanges 41 and 42. Openings 43 areprovided in flanges 41 and 42. These openings are adapted to be alignedwith suitable openings 44 in the forward portion of the U-shaped sidemembers 12 and 14 of outer frame 10. The means for detachably connectingthe inner frame and the outer frame preferably comprise screws 45.

Heat insulation 46 may be affixed to the inside portions of U-shapedside members 12 and 14 and rear member 18 to minimize heat transferlosses through the walls of heating assembly 8. The helical coil 31 liesin a plane generally transverse to the path of the air flowing throughthe duct 9 to the room to be treated. During the heating cycle whenadditional heat may be required to comfortably heat the area, a suitablecontrol 47 mounted in the control box assembly 38 may be actuated topermit electrical current to flow through the helical coil resistancewires and heat the same. Lines 48 connect control 47 to a source ofelcetrical current (not shown).

As is apparent, the inner frame is of a drawer-type construction thatmay be readily removed from and replaced within duct 9. Heating assembly8 may comprise the connecting means between air outlet 4 of casing 2 andduct 9 or the heating assembly may be placed within the duct at a pointmore remote from the casing.

By virtue of my simple heating assembly construction, it is now possibleto expeditiously remove the heater element for repair in the event thatthe helical coil 31 is broken or burned through. This is accomplished byremoving the screws 45 and sliding the inner frame 11 from the outerframe 10. The repairman can substitute a new drawer or inner frame forthe damaged one. Thus, even if the indoor section of the heat pumpsystem is placed within a closet or other confined place, the heaterelement or coil 31 is readily accessible. The air conditioning systememploying the novel heating assembly is much enhanced and the indoorsection thereof can be placed in locations heretofore not considered tobe desirable.

While I have shown only a preferred embodiment of the present invention,it is obvious that changes may be made by those persons having skill inthe art without departing from the principles of the invention and Idesire that the scope of my invention be limited only by the appendedclaim.

I claim:

In an air conditioning system, the combination of a casing having an airinlet and an air outlet therein, said casing having a raised lipsurrounding the air outlet; a duct for conducting air from the casing toan area to be treated, said duct having a flange thereon; and a heatingassembly for heating air passing through the duct, said heating assemblycomprising an outer frame including U-shaped side members and a rearmember, a flange extending from each side member engaging the lipsurrounding the air outlet, support members connecting the ends of eachU-shaped member and forming channels to slidably receive an inner frame;an inner frame including side members, a rear member and a transversebrace member, said side members being slidably supported on the supportmembers, rods extending between the trans verse brace member and therear member, insulators, supports mounted on said rods carrying theinsulators, and a helical coil supported by said insulators; a controlbox connected to the inner frame side members including a casing havingflanges adapted to be connected to the U- shaped members, means fordetachably connecting the casing flanges to the U-shaped members, andmeans for securing the flange of the duct to the outer frame.

References Cited in the file of this patent UNITED STATES PATENTS1,307,198 Harth June 17, 1919 1,829,765 Spalding Nov. 3, 1931 1,841,361Bulkeley Jan. 19, 1932 2,115,567 Anderson Apr. 26, 1938 2,282,373Minkler et al Apr. 12, 1942 2,492,316 Osterheld Dec. 27, 1949 2,672,734Ditzler et al Mar. 23, 1954 2,732,475 Averill Jan. 24, 1956 FOREIGNPATENTS 137,927 Australia July 12, 1950

